1. Field of the Invention
The present invention relates to a communication method and apparatus.
2. Description of the Related Art
In addition to personal computers and mobile telephones, such devices as digital TVs, digital camera and digital video recorders also now come equipped with a communication function. This means that even the home can have a network that includes a plurality of communication apparatuses.
Further, the foundation is now being laid for a system in which once a call has been set up using a call control protocol, the above-mentioned communication apparatus is connected to a communication apparatus on a different network so that these may communicate with each other.
In Japanese Patent Application Laid-Open No. 2005-033528, for example, a service provider candidate list of service providers used by a first network is transmitted to a second network. The second network creates a service provider candidate list that matches the service provider candidate list received from the first network and sends the created candidate list back to the first network. The user on the side of the first network selects a suitable service provider from the list that has been sent back.
In a case where a plurality of communication apparatuses exist on a network, it is necessary to select a second service provider that is suited to the functions of a first service provider in order that the first and second service providers may be connected and perform data communication for a prescribed purpose.
For example, a service provider that reproduces video data cannot perform the intended data communication unless it is connected to a service provider that transmits video data. A service provider that reproduces video data is, for example, a digital TV, and a service provider that transmits video data is, for example, a digital video recorder.
If unsuited service providers are selected, the selected service providers may not be capable of communicating with each other.